Is Time Truly a Dimension or Something Else Entirely?

[nutgeb]

This topic is not capable of a definitive answer. One can somewhat arbitrarily but perfectly reasonably create a coordinate system with 3 spatial dimensions and 1 time dimension. It happens to be useful in simplifying the mathematical portrayal of certain concepts of relativity. But the fact that it is mathematically useful for that purpose imparts it no unique significance to "spacetime" as a physical concept or system. For example, one could imagine an alternative coordinate system in which the defined "dimensions" include 3 spatial dimensions, 1 time dimension, 3 color dimensions, 3 density dimensions, 3 temperature dimensions, 3 pressure dimensions, etc. But our ability to define that coordinate system and use it in calculations does not mean that this system of "space-time-color-density-temperature-pressure" is somehow more physically "real" or "unique" than the individual categories of dimensions from which it is built. In the same sense, the concept of "spacetime" is no more real or meaningful than treating the spatial dimensions separately from the time dimension.

 

[Dale]

In the same sense, the concept of "spacetime" is no more real or meaningful than treating the spatial dimensions separately from the time dimension.

I disagree. If it can predict the results of experiments better then it is more real and more meaningful.

Otherwise why would we bother doing experiments? If the results of scientific experiments don't tell us anything about the "meaningfulness" of our scientific theories then we should have just stayed with pre-scientific superstitions.

 

[nutgeb]

I'm just saying that although coordinate system based on a "bent" spacetime with a "straight" geodesic traveling through it is convenient and useful, that happenstance doesn't disprove that on the contrary the geodesic is "bent" and the spacetime is "straight." We can disagree in our opinions about this but there is no way currently to come to a definitive conclusion because we don't know the physical mechanism by which gravity works. Both possibilities should be treated as scientifically reasonable.

 

[atyy]

I'm just saying that although coordinate system based on a "bent" spacetime with a "straight" geodesic traveling through it is convenient and useful, that happenstance doesn't disprove that on the contrary the geodesic is "bent" and the spacetime is "straight." We can disagree in our opinions about this but there is no way currently to come to a definitive conclusion because we don't know the physical mechanism by which gravity works. Both possibilities should be treated as scientifically reasonable.

I think what you said is true even with in GR.

Thorne, Black Holes and Time Warps, 1994: Is spacetime really curved? Isn’t it conceivable that spacetime is actually flat, but clocks and rulers with which we measure it, and which we regard as perfect in the sense of Box 11.1, are actually rubbery? Might not even the most perfect of clocks slow down or speed up, and the most perfect of rulers shrink or expand ...? Wouldn’t such distortions of our clocks and rulers make a truly flat spacetime appear curved? Yes.

 

[Dale]

Both possibilities should be treated as scientifically reasonable.

In this post you are referring to different interpretations of the same theory, that is not what I was objecting to above. I (perhaps mistakenly) understood you above to be talking about Newtonian mechanics and special relativity, where there are experimental differences.

Personally, I have never been terribly interested in different interpretations of the same theory, all that matters are the predictions a theory makes and how well those predictions agree with experiments. The stories we tell ourselves are not terribly important. I think that a person should be aware of all of the different interpretations and use each of them when convenient. The "default" interpretation should always be the simplest one.

That said, in the math of all modern physical theories time is a dimension, and the theories agree very well with experiment. The interpretation you use does not change the math. Therefore, IMO, the topic is capable of a definitive answer in the affirmative.

 

[Sjorris]

I don't agree with you DaleSpam,
Interpretating a theory allows for completing, expanding or otherwise enhancing it, because you can venture qualitatively where you usually wouldn't go mathematically. QM in it's early days profited from this, and when Einstein tried to interpret Maxwell's equation he stumbled upon certain ideas which would later lead to SR (I'm referring to the thought-experiment said to be performed by Einstein in which he imagined himself being in the frame of reference of a photon, 'riding a beam of light' so to say).

Momentarily, no one has a clue how to distinct the two earlier named interpretations of how exactly spacetime is curved (spacetime itself or the geodesic), but when both interpretations excist, one might sooner or later come up with some way to verify which interpretation is the 'right' one, which one more closely resembles reality (or it may turn out the two interpretations are in fact effectively identical). Qualitative interpretation is, in my opinion, far more important than mathematical, as math is 'just' a tool (be it a very good one) and usually less understood by humans than thought in native language.

If you see a theory just as a complicated calculator to verify experiments with, then what is the point of having the theory?

 

[Fredrik]

If you see a theory just as a complicated calculator to verify experiments with, then what is the point of having the theory?

The point is that there's no better alternative. There's no way to directly obtain knowledge about the universe, so the best we can do is to come up with a theory that predicts the (probabilities of) results of experiments, and then perform the experiments. The only real facts in science are of the form "prediction A of theory B agrees with experiment C with accuracy D".

This doesn't mean that I disagree with your view that it might be useful to examine the interpretations more closely. It's certainly possible that one interpretation suggests a generalization of the theory in a more obvious way than the others.

 

[Dale]

Momentarily, no one has a clue how to distinct the two earlier named interpretations of how exactly spacetime is curved (spacetime itself or the geodesic), but when both interpretations excist, one might sooner or later come up with some way to verify which interpretation is the 'right' one, which one more closely resembles reality (or it may turn out the two interpretations are in fact effectively identical).

There is never any way to experimentally choose between two interpretations of the same theory, that is what distinguishes a new interpretation of an existing theory from a new theory.

Qualitative interpretation is, in my opinion, far more important than mathematical, as math is 'just' a tool (be it a very good one) and usually less understood by humans than thought in native language.

I guess here is our real disagreement. I find the math far more important than the qualitative "story" that we tell around the math. The reason is that both are "just tools" for understanding the universe, but the math is inherently logical, whereas the English is open to illogic, misunderstanding, and confusion. The vast majority of the posts on this forum are a direct result of something being mistakenly lost or added in the math-to-English translation. The universe doesn't "speak" English, but if it behaves logically then math is its language.

 

[Sjorris]

There is never any way to experimentally choose between two interpretations of the same theory, that is what distinguishes a new interpretation of an existing theory from a new theory.

Of course both interpretations are initially effectively the same, however as Frederik pointed out certain interpretations can more easily lead to generalizations and/or expansions, offering the possibility of predictions the other interpretation doesn't. Technically you are right though, the moment one interpretation yields different results it's in fact a different theory.

I guess here is our real disagreement. I find the math far more important than the qualitative "story" that we tell around the math. The reason is that both are "just tools" for understanding the universe, but the math is inherently logical, whereas the English is open to illogic, misunderstanding, and confusion. The vast majority of the posts on this forum are a direct result of something being mistakenly lost or added in the math-to-English translation. The universe doesn't "speak" English, but if it behaves logically then math is its language.

Ok, I might have been talking too much in absolutes. English is the language of english people, math and logic is the language of the universe. A mathematical formulation of a theory is far more rigid and not really open for confusion and/or misunderstanding, however when 'speculating' I tend to think in my own human language, and not in mathematics, especially in fields where I'm not experienced. Ideally, it would be superior when I could speculate and extrapolate theories purely in mathematics, however humans are limited in their understanding and use of mathematics, so that's why I prefer human language for such cases.
Obviously, for well explored fields of science a mathematical formulation is far better in every way.

I'm not finished with this post but I have to go, I'll post again later.

 

[Dale]

Ok, I might have been talking too much in absolutes.

No problem. I am very guilty of the same!

 

[yinfudan]

I hope I could try to answer boysherpa's question, although I just learned Special Relativity lately. Boysherpa has a very good point - what is the definition of time. It is important to understand what makes time before we discuss if time is a dimemsion.

I have a feeling that physics cannot measure the absolute value for anything; it can only measure the relative value against other things. For example, when you measure the length, you are measuring how many ticks on the ruler. So eventually, the length is defined as how far the light travels in a second, (say one meter is 1/300000 of the distance the light travels in a second). Probably the length can also be defined as how big is a fixed sized object, (say one meter is the length of n neutrons put side by side).

Because physics only measure the relative value, not the absolution one, we cannot even tell if the universe is changing if the measurement unit is changing as well. For example, can we tell if everything in the universe shrinks by half last night? The ruler will shrink by half as well; the atom size will shrink by half; the light will travel slower by half - but one light second is still 300000 times as long as a meter ruler. So probably we will notice nothing has ever changed.

Now let us go back to time, how is time defined? I think time is defined in a relative way as well. It is a measurement of how fast other things happen compared to a standard motion - for example, a clock tick. Similarly, if other things take only half time, but a clock runs double speed, we will not notice anything changed.

Traditionally, clock is made of mechanic devices, for example, a spring oscillator. A second is defined as how many times the oscillator runs a full cycle. Thus, clocks having higher frequency oscillators tend to have higher precision. In Special Relativity, Einstain defines time using light with a light clock. It counts how many time a light point bounces between two mirrors.

But the idea to define time with light is actually a concern to me: Since we define length with light and time (the distance light travels within a certain time), now we are defining the time with light and distance again (the amount of time the light travels between two mirrors). Is there any circular definition?

Or can I think this way: since the propagation of light creates both distance and takes time. Both length and time are defined with the help of light. So that it is inevitable that space and time are not separatable, and form so called spacetime, even though space and time are totally different things?

 

[atyy]

But the idea to define time with light is actually a concern to me: Since we define length with light and time (the distance light travels within a certain time), now we are defining the time with light and distance again (the amount of time the light travels between two mirrors). Is there any circular definition?

Or can I think this way: since the propagation of light creates both distance and takes time. Both length and time are defined with the help of light. So that it is inevitable that space and time are not separatable, and form so called spacetime, even though space and time are totally different things?

Yes, we cannot do that. Ohanian talks about this in his book "Einstein's Mistakes". Originally, we defined time in a way such that Newton's laws are true in a class of reference frames which we call "inertial". Then using those laws we measure the speed of light to be the same in all inertial frames. Then we know about Lorentz invariance. Nowadays we are so confident of Lorentz invariance and the constancy of the speed of light, that we define the speed of light to be constant without fear that we will cause objects moving at low velocities to disobey Newton's laws.

 

[Makep]

Time is the fourth dimension of existence and must be expressed by all moving systems. What would happen if relativity is not true and everything / systems in the universe stop moving. They would, probably, regress into oblivion. Matter would disappear, and space would disappear as well, then existence would also mean nothing.

 

[Sjorris]

That's highly unscientific and doesn't really mean anything... Time also is a fundamental quantity in non-moving systems, because nothing is in fact stationary, Only simplifications sometimes are called steady state, but obviously on the quantum level there is a lot going on which is dependant to time. Also, non-moving systems is kind of a absolute system, but we know only inertial can be absolute, systems moving at a constant speed might as well be standing still, or the other way around, there's no way to tell.
When relativity is not true, nothing really changes. Newtonian motion also desribes most of the observed behaviour very well, it was only after the discovery of relativity that effects caused by SR/GR were observed, not before (except that c is a constant). I don't really see any fundamental problems with GR/SR being not-existent.
For the universe to 'stop moving', well, we don't really know what happens then I guess, at the moment we don't even know if the (visible) universe is expanding or collapsing (as far as I'm concerned, there's a lot of conjecture in this topic and it seems to change from year to year), let alone predict what happens when everything is instantenously stopped everywhere in the universe. If you imply that everything will stay stationary, well, I don't think that's possible, where would all the energy come from to stop the huge amount of mass everywhere from accelerating?

 

[Austin0]

Well, I'll give it a shot. Distance isn't made of particles or waves. Is distance physical?

Time, like distance, isn't composed of particles or waves, but is used to describe intervals between physical events. This is why time is referred to as a dimension, because, like distance, two events can be separated by it. And this simple fact is the reason time (and distance) are useful concepts.

And any useful definition of time will be very similar to a useful definition of distance, in the sense that both are intervals between "physical things", not "physical things" themselves.

So, yes, time is a dimension instead of a substance.

Just a comment from the onlookers. I think your comments were very relevant and insightful.
But it appears to me that the main thrust of this debate is not about time as a concept like distance but about time as a concept like space. SO this is equivalent to trying to agree on the nature of space. I. e. Is it nothing [vacuum] ,aether, quantum foam ,etc, etc.
So some of you are talking about time [like distance] as a system of measuring intervals
[between events] and some of you are talking about time as an entity like space and considering its possible qualities or even existence outside of human abstraction.
Not much hope of a meeting of the minds here it would seem.

 

[Makep]

That's highly unscientific and doesn't really mean anything... Time also is a fundamental quantity in non-moving systems, because nothing is in fact stationary, Only simplifications sometimes are called steady state, but obviously on the quantum level there is a lot going on which is dependant to time. Also, non-moving systems is kind of a absolute system, but we know only inertial can be absolute, systems moving at a constant speed might as well be standing still, or the other way around, there's no way to tell.
When relativity is not true, nothing really changes. Newtonian motion also desribes most of the observed behaviour very well, it was only after the discovery of relativity that effects caused by SR/GR were observed, not before (except that c is a constant). I don't really see any fundamental problems with GR/SR being not-existent.
For the universe to 'stop moving', well, we don't really know what happens then I guess, at the moment we don't even know if the (visible) universe is expanding or collapsing (as far as I'm concerned, there's a lot of conjecture in this topic and it seems to change from year to year), let alone predict what happens when everything is instantenously stopped everywhere in the universe. If you imply that everything will stay stationary, well, I don't think that's possible, where would all the energy come from to stop the huge amount of mass everywhere from accelerating?

Am I confused or are you confusing in your opening statements with regard to movement. Consider your statement,

Time also is a fundamental quantity in non-moving systems, because nothing is in fact stationary, Only simplifications sometimes are called steady state, but obviously on the quantum level there is a lot going on which is dependant to time

.
There really can' be an existence without time. To generate time, a body must move - whether accelerating or at a constant velocity is not the issue.To exist without time is to be in the inertial frame of a bigger system - hence, still moving.

 

[Makep]

Just a comment from the onlookers. I think your comments were very relevant and insightful.
But it appears to me that the main thrust of this debate is not about time as a concept like distance but about time as a concept like space. SO this is equivalent to trying to agree on the nature of space. I. e. Is it nothing [vacuum] ,aether, quantum foam ,etc, etc.
So some of you are talking about time [like distance] as a system of measuring intervals
[between events] and some of you are talking about time as an entity like space and considering its possible qualities or even existence outside of human abstraction.
Not much hope of a meeting of the minds here it would seem.

Distance is space isn't it? Only that distance is the intervening space between two or more physical entities or events. So speaking about time as a concept like space is just like speaking about time as a concept like distance. In, fact both are same.

 

[john 8]

Hi everybody. I just recently joined this forum because I have been reading through the various sections and find it a lot more stimulating than other discussion forums.

I have been thinking about this subject myself and I may have some idea of what john 8 is trying to get at so here's my two cents.

To define time in both a mathematical and a physically measurable sense in a unified form we turn to geometry.

Now I'm not going to repeat the disccussion on general relativity and how time is defined through the change in events because that has already been well discussed. What I will do however is state that given a universal geometry G which contains the set of all events (usually in mathematics we denote it as omega) possible in accordance with global set of processes in the universal system, contains the starting point for which I define time.

Given this geometry G, a time-line is defined as the path taken from an initial event A to a final event B. Any mathematical expression will suffice as long as they unambiguously differentiate one unique time-line from another.

So in this respect time is defined as the distance traversed within the global space-time. This distance is measurable using the same notion of length that is used in normal euclidean geometry (in this case the metric is given by the square root of the sum of the squares).

If one event lies in the global geometry G at a point P and a possible future event lies at point F in the geometry then time is defined purely as the path taken to reach F from P. We can measure this using advanced geometric techniques.

In a multidimensional geometric theory we can use a few tools that we have developed as a result of mathematics. The notion of relative measure (or angular measure) is important as well as the notion of absolute measure (defined from the metric). With angular measure we are defined a form of measure of two points relative to some origin. By using the properties of given geometries and by measuring as accurately as possible the results that are the projection onto our currently perceptible 3-space, we can infer a particular geometry that corresponds to a set of physical processes P and thus through a metric define what we mean by "time".

Now if we build the relation between our universal geometric structure G and a local intuitive
structure (i.e. a local R^3 structure with orthogonal axis) then we can relate distance in
the global structure G to corresponding distance in the intuitive structure. This essentially
establishes a link between "intuitive" time and "universal time". The process I describe is
akin to linking a string theoretic definition of time in multidimensional universe or one of time
in an einsteinian universe to that of a Newtonian universe.

Once the link has been made between the various theories all you need to do is use a geometric physical measuring device (eg a ruler) and a known physical process (such as the behaviour of light) to measure time as time directly correlates to distance.

If I'm wrong I welcome any comments as I have only really just started to learn this kind of thing properly so if I'm wrong I'd welcome a seasoned expert to fix up where an amendment is needed.

I hope this helps.

Matthew

Hi Matthew.

You have stated much in your explanation of time. In all that you said you did not state if time was a physical thing or not. You said that you have recently join this form. Well I have to say that I have been asking the simple question of someone who thinks that time is a physical thing to just give evidence of this. A reference, a definition, something.

Some state that time is a real physical thing and never point to a real physical perception or reference. Look, either time is a physical thing or it isn't. If you say that time is a physical thing than give some supporting evidence, simple as that.

All physical things in this universe are made of energy. This energy comes in two forms,either a particle or a wave. If you know of a different form please say so. Otherwise, if you think time is a physical thing than just use scientific references or observations to back up your claim that time is a real physical thing.

There may be those on this form that know me and discount what I have to say about time not being a real physical thing, that is fine, but these same people who say that I am wrong, an idiot, that I am just "trolling" have never given any scientific evidence that I am wrong and they are right that time is a real physical thing.

This whole discussion can be put to rest if someone can provide any shread of evidence that time is a physical thing. Simple as that.

Just because someone believes or hopes that time is a real physical thing does not make it so. Where is the science that time is a physical thing.

Look, I have been saying that time is not a physical thing on this form for a while now. If anybody has given any evidence of the physical nature of time on this form or any form for that fact, than just post that link so that I can be shown that I am in error.

I will state for the record one more time, time is not a physical thing due to the lack of evidence that it is and the fact that those who state that time is a physical thing will not give any evidence to back up their assertion.

If you say time is a physical thing than just give some supporting data.

 

[Al68]

All physical things in this universe are made of energy. This energy comes in two forms,either a particle or a wave.

Time isn't a particle or wave, so no one would claim that time is a physical thing by your definition.

Some might want to use a different definition, like calling a dimension that separates events "physical", so that time and space are physical, but that's a matter of semantics only. And you know what they say about arguing about semantics.

 

[john 8]

This topic is not capable of a definitive answer. One can somewhat arbitrarily but perfectly reasonably create a coordinate system with 3 spatial dimensions and 1 time dimension. It happens to be useful in simplifying the mathematical portrayal of certain concepts of relativity. But the fact that it is mathematically useful for that purpose imparts it no unique significance to "spacetime" as a physical concept or system. For example, one could imagine an alternative coordinate system in which the defined "dimensions" include 3 spatial dimensions, 1 time dimension, 3 color dimensions, 3 density dimensions, 3 temperature dimensions, 3 pressure dimensions, etc. But our ability to define that coordinate system and use it in calculations does not mean that this system of "space-time-color-density-temperature-pressure" is somehow more physically "real" or "unique" than the individual categories of dimensions from which it is built. In the same sense, the concept of "spacetime" is no more real or meaningful than treating the spatial dimensions separately from the time dimension.

I disagree, this topic is capable of a definative answer. Things are either physical or they are imagined. If it is physical there will be perceptable evidence of it's existence. Simple as that. Is it real or imagined? Come on people, use science to figure this out.

Would you say that the topic of whether a rock is a real physical thing is a topic that has no definative answer? What about light? Is that topic up in the air, no definative answer?
What about air for that matter? Is that too just a topic that has no definative answer as to if it is a real physical thing? Come on! If something physically exists there is no debate, It exists due to it's actual physical nature.

Dimensions, space-time are either real physical thing or they are not. It is that simple. Where is the confusion? Here are your choices in solving this mystery for you.

Dimensions, space-time are real physical things (here is where you give scientific evidence).

If there is no evidence to support your assertion that dimensions or space-time are real physical things than either there is no evidence or it has not been found.

If you say that these things are real physical things but the evidence has not been found, than explain how you came to this conclusion.

 

[john 8]

Time isn't a particle or wave, so no one would claim that time is a physical thing by your definition. .

My definition of physical thing is the same as any standard dicionary or reference book.

I am asking someone who thinks that time is time a physical thing to give evidence of this according to perception, by scientific definitions or standard dictionary definitions?



Physical and thing that I am refereing to are the same definitions defined in all standard reference books.

State if you think time is a physical thing. If you think time is a physical thing than just give the evidence of this as per what science deems to be a physical thing.

Some might want to use a different definition, like calling a dimension that separates events "physical", so that time and space are physical, but that's a matter of semantics only. And you know what they say about arguing about semantics.

Look up the definitions of physical and thing if you have to. The applicable definitions to this topic are what I am referring to.

If you think time is a physical thing than just tell me what definition of time, physical, thing, that you are using so that I can understand exactly what you mean.

If you say that time is physical thing than just give the scientific evidence to support your claim. Your next post in reference to this should contain the evidence, not more diversions and analysis of semantics.

Give your evidence!

 

[Al68]

Your next post in reference to this should contain the evidence, not more diversions and analysis of semantics.

I already said time was not a "physical thing" by that definition. Why should my post contain evidence for something I don't believe?

And why would you object to semantics when your question is a semantic one?

Nobody in this thread has claimed that time was made of particles or waves, so if you take the semantics out of your question, there is nothing left.

 

[john 8]

I hope I could try to answer boysherpa's question, although I just learned Special Relativity lately. Boysherpa has a very good point - what is the definition of time. It is important to understand what makes time before we discuss if time is a dimension.

The definition of time can be found in any standard scientific reference book or standard dictionary. There is your definition of time.

I have a feeling that physics cannot measure the absolute value for anything; it can only measure the relative value against other things. For example, when you measure the length, you are measuring how many ticks on the ruler. So eventually, the length is defined as how far the light travels in a second, (say one meter is 1/300000 of the distance the light travels in a second). Probably the length can also be defined as how big is a fixed sized object, (say one meter is the length of n neutrons put side by side)..

You have a feeling! Is that what this form is all about? Feelings. You just gave your own personal definition of time that is not found in any standard reference book. Stick to science and standard definitions please.

Now let us go back to time, how is time defined? I think time is defined in a relative way as well. It is a measurement of how fast other things happen compared to a standard motion - for example, a clock tick. Similarly, if other things take only half time, but a clock runs double speed, we will not notice anything changed.)..

You just gave your definition of how you think time is defined. Why? Use standard definitions. Your interpretations are irrelevant to this topic, this is a science form. Agreed.

Traditionally, clock is made of mechanic devices, for example, a spring oscillator. A second is defined as how many times the oscillator runs a full cycle. Thus, clocks having higher frequency oscillators tend to have higher precision. In Special Relativity, Einstain defines time using light with a light clock. It counts how many time a light point bounces between two mirrors.

But the idea to define time with light is actually a concern to me: Since we define length with light and time (the distance light travels within a certain time), now we are defining the time with light and distance again (the amount of time the light travels between two mirrors). Is there any circular definition?

Or can I think this way: since the propagation of light creates both distance and takes time. Both length and time are defined with the help of light. So that it is inevitable that space and time are not separatable, and form so called spacetime, even though space and time are totally different things?

Look, time is already defined in many dictionaries and scientific reference books. There is no debate on the definition of time.

After everything that you said what have you actually said? What point are you trying to make?

Is time a physical thing or not? You did not say either way.

 

[john 8]

I already said time was not a "physical thing" by that definition. Why should my post contain evidence for something I don't believe?

And why would you object to semantics when your question is a semantic one?

Nobody in this thread has claimed that time was made of particles or waves, so if you take the semantics out of your question, there is nothing left.

Hi Al68.

There is a misunderstanding here. You used a quote that I made toward chiro in his/her post #118 and then you made a response to me using this quote. I was not originally discussing anything with you. From your dialogue to me I made the mistake that you may have been disagreeing with my statement that time is not a real physical thing.

As far as you saying that nobody in this thread has claimed that time was made of particles or waves, you are right, no one used those words to describe time, although DaleSpam has stated that time is a physical thing numerous times on this thread, post #61 for example.

So if something is physical than it is either made of particles or waves. Right? If you think a physical thing can be made of something other than a particle or wave please let me know.

On page one of this thread post #18 I state that time is not a real physical thing. This is my stand. In the last sentence of this post I ask anyone who thinks that time is a real physical thing to give an explanation of how this could be.

If you start from post #18 you will see that there are those who disagree with my statement that time is not a real physical thing. These same people do not give any evidence as to how I am incorrect in my statement.

This whole thread is full of discussion about time, yet most will not say if this time thing that they are talking about is a real physical thing or not. Those that do say time is physical do not give any scientific proof of this.

If you want to see what I am talking about just go to page 4, post #59 and you will see examples of people that disagree with my statement that time is not a real physical thing yet just give these non specific, run around answers as to how I am incorrect, some go as far as calling me names.

Look, don’t you think that if I was in error that someone would have given definitive proof of my error and this whole subject would be resolved. But here they are stating that time is a real physical thing or at least disagreeing with me which would mean that they think that time is a real physical thing, yet not one shred of evidence.

I will state my assertion anew. Time is not a physical thing. If anyone disagrees with this statement, than just show some evidence that time is a real physical thing. My definitions for time, real, physical, and thing are the same definitions used by any standard dictionary or scientific reference book.

This should be a very simple exercise to disprove my assertion that time is not a real physical thing if in fact time is a real physical thing.

Now that I have gotten that out of the way, I just want to make sure that I understand you Al68, you say that “time was not a physical thing by that definition”. Fine, but do you think that it is physical by some other definition? Do you think that time is a physical thing? Yes/ No.

 

[Al68]

Now that I have gotten that out of the way, I just want to make sure that I understand you Al68, you say that “time was not a physical thing by that definition”. Fine, but do you think that it is physical by some other definition? Do you think that time is a physical thing? Yes/ No.

Sure, if the word physical is used to mean "pertaining to the physical sciences, esp. physics".

That's what I mean by semantics. That words have multiple definitions and a statement that is true by the definition used by the person making the statement may be false if a different definition is assumed by someone else. In this case both definitions are valid and commonly used.

Obviously those that said time is physical were not using the definition you assumed they were.

If I claim to have a spare tire in my boot, would you ask me to provide evidence of it using a definition (foot wear) that I wasn't using when I made the claim?

When a word has multiple common definitions, you cannot assume that a claim made by someone else is using the one definition you choose of many.

 

[john 8]

Originally Posted by john 8

“Now that I have gotten that out of the way, I just want to make sure that I understand you Al68, you say that “time was not a physical thing by that definition”. Fine, but do you think that it is physical by some other definition? Do you think that time is a physical thing? Yes/ No.”

Sure, if the word physical is used to mean "pertaining to the physical sciences, esp. physics".

That's what I mean by semantics. That words have multiple definitions and a statement that is true by the definition used by the person making the statement may be false if a different definition is assumed by someone else. In this case both definitions are valid and commonly used.

Obviously those that said time is physical were not using the definition you assumed they were.

If I claim to have a spare tire in my boot, would you ask me to provide evidence of it using a definition (foot wear) that I wasn't using when I made the claim?

When a word has multiple common definitions, you cannot assume that a claim made by someone else is using the one definition you choose of many.

You have not answered the question. The question was “Do you think that time is a physical thing?”

Emphasis on thing. I am not asking if time pertains to the physical sciences. Is time a thing, a form of energy. There are no semantic problems here.

Do you think time is a physical thing? Yes/No

 

[meteor9]

Matthew , if you gather and mention all the mathematic and physics formula to demonstrate that time is a physical and measurable dimension, even though referring to einstein and Newton or all the other accredited physicists and mathematicians , you can never convince some skeptical independant thinkers like me that time is a measurable dimension. Many many times in my life I found myself in some strange situations where I moved from point A to B without feeling that some conventional time has passed . Of course witnesses told me that 48 hours were passed but I hadn't the least notion of that, it was like time has been escaped or there was some hole in my mind where the time had no meaning to me . So I deduce that time remains a 'mystery' which is related to our brain functioning , if you manipulate some parts of the brain , the notion of time could completely disappear, and you lose the ability of anticipation , then you will live without any future and just will be present at an eternal present . Animals live so , they are unable to anticipate so they don't have any notion of their future death .

 

[Al68]

Emphasis on thing. I am not asking if time pertains to the physical sciences. Is time a thing, a form of energy. There are no semantic problems here.

Do you think time is a physical thing? Yes/No

No, assuming that "thing" means "a material object without life or consciousness".

Yes, assuming that "thing" means "anything that is or may become an object of thought" or "a thought or statement: I have just one thing to say to you" or "a particular, respect, or detail: perfect in all things".

 

[Fredrik]

Well I have to say that I have been asking the simple question of someone who thinks that time is a physical thing to just give evidence of this. A reference, a definition, something.
[...]
This whole discussion can be put to rest if someone can provide any shread of evidence that time is a physical thing. Simple as that.

Please don't start this nonsense again.

Only crazy people think that time is a physical thing according to your definition of "a physical thing". (Note that we didn't know what your definition was when this discussion started). There are however other reasonable ways to define what "physical" means. For example, you could define it so that anything measurable is considered physical. Another option is to define it so that any concept that's defined by a theory and (according to that same theory) affects the probabilities of the possible results of some experiment is considered physical.

Neither I nor anyone else had claimed that time is physical according to your definition until petm1 did it in #83
[...]
If you have a question about science, then ask it. If not, I suggest you try to find something better to do than this.

 

[meteor9]

No , time is not a physical thing !

 

[Dale]

meteor9 and john 8,

You have each stated that time is not physical, so if that were true there would be two possibilities:
(1) Time is not physical, but it is essential to any correct theory of physics
(2) Time is not physical, so it is not essential to any correct theory of physics

Since this is a proposition of the form "A" or "not A" either (1) or (2) must be true. Which do you agree with?

If you agree with (1) then this argument is a purely semantic argument about the definition of the word "physical". However, if you agree with (2) then it is up to you to demonstrate that by providing such a theory.

I await your answer. I hope it is (2) because semantic arguments are boring.

 

[meteor9]

Of course I agree with the second possibility, a 'correct' theory of physics has not the least correlation with time, time being just a convention for the convenience of our experiments , the correct theory of physics deals exclusively with mass and energy . Do you think that C14 cares about the time? Or all the other known and unknown elements ? They are just there in some eternal present revealing mutations not because of time but because of their intrinsic qualities and interactions . If you want to deal with the correct theory of physics , you should always mute it at -0- . If time is excluded from all physics theories then you are in a 'correct' ground .

 

[A.T.]

If time is excluded from all physics theories then you are in a 'correct' ground .

Please show us an example how excluding time changes the prediction, so that it is more 'correct' (agrees better with observation).

 

[Dale]

Of course I agree with the second possibility, a 'correct' theory of physics has not the least correlation with time, time being just a convention for the convenience of our experiments ,

OK, I can at least respect that position. So does such a theory exist?

the correct theory of physics deals exclusively with mass and energy .

How would such a theory define energy without reference to time? Also, would your time-free theory also be space-free or is space OK?

 

[john 8]

meteor9 and john 8,

You have each stated that time is not physical, so if that were true there would be two possibilities:
(1) Time is not physical, but it is essential to any correct theory of physics
(2) Time is not physical, so it is not essential to any correct theory of physics.

If time does not exist as a physical thing then there is only one possibility, it does not exist as a physical thing.

DaleSpam, Is time a physical thing according to the scientific definition of time? You have avoided this over and over. Just provide the evidence to back up your claim.

Since this is a proposition of the form "A" or "not A" either (1) or (2) must be true. Which do you agree with?

If you agree with (1) then this argument is a purely semantic argument about the definition of the word "physical". However, if you agree with (2) then it is up to you to demonstrate that by providing such a theory.

I await your answer. I hope it is (2) because semantic arguments are boring.

I have already stated that the definitions of time , physical, and thing are the same definitions used in any standard scientific dictionary or reference book. There is no confusion about what I mean. I say that time is not a physical thing.

Why don’t you provide the definition of time that you are using that shows that I am wrong.

Time is either a physical thing or not. If it time is a physical thing then science would say so. All of my terms are defined and all the terms back up my claim that time is not a physical thing.

It is up to you to provide evidence to the contrary if you disagree with me and science.

DaleSpam, let's make this simple. Just state if you think that time is a physical thing. Just yes or no. that’s all, no explanation, no evidence, just a simple yes or no. Can you do that?

 

[DrGreg]

john 8 keeps asking if time is a "physical thing". He has defined "physical thing" to be either a wave or a particle. So he is asking if time is a wave or a particle.

So I invite everyone taking part in this thread to state explicitly, "no, time is not a wave or a particle" and then maybe john b will stop going on about this and we can discuss something more interesting instead.

 

[Fredrik]

Time is not a wave or a particle.

 

[Dale]

The argument with john 8 appears to be purely semantic. I agree with him tha time is neither a wave nor a particle.

The discussion with meteor9 looks more interesting.

 

[meteor9]

Yes , such a theory exists. This is a correction of Einstein theory E=mc2 . When Einstein considered the velocity2 necessary to the mass, and given his vision of the curvature of time-space , where at some point , the time and the space become a unique entity , then we can conclude that space-free in this theory is relevant .
Energy has nothing to do with time neither with space. Why should the definition of energy refer to time , while we agree that time is not wave nor particle ? For example when you burn the metane gas which produces energy , is it related to time ? Or when you turn on your electric light bulb , does it depend on time ? Metane, butane, electricity, etc. produce energy without any relation to time .
As for the 'prediction' which is as I said before just a human brain/mental convention , everything can 'exist' even without this convention .
Don't forget that the most part of our universe, our 'world' , our body and everything is make up of vacuum. Between molecules and atoms we have huge amount of vacuum . If you subtract this vacuum , our universe with all its tremendous galaxies , then our 'existence' would become as tiny as a bean . How do you explain this vacuum ? If time and space are perceived as we perceive them , it is because of this vacuum and without this vacuum we would have no space and no time , but just a mass possessing an incredibly huge amount of energy , so my theory is : E=m .

 

[Dale]

Energy has nothing to do with time neither with space. Why should the definition of energy refer to time

Energy is force times distance, force is mass times acceleration, and acceleration is change in velocity over time. So energy is mass times change in velocity over time times distance. So space and time are a fundamental part of the very definition of energy. You will have to do more than just shrug and say that they have nothing to do with each other.

 

[Hootenanny]

so my theory is : E=m

I agree with you, provided that the mass is measured in MeV/c², or if we're in natural units

 

[meteor9]

LOL Hootenanny ! Lot of hahaha , i don't have emoticons here to express my feelings.

DaleSpam , it's ok , then take it for whatever you want .

 

[john 8]

john 8 keeps asking if time is a "physical thing". He has defined "physical thing" to be either a wave or a particle. So he is asking if time is a wave or a particle.

So I invite everyone taking part in this thread to state explicitly, "no, time is not a wave or a particle" and then maybe john b will stop going on about this and we can discuss something more interesting instead.

Thank you. Thank you. Thank you.

Now we are getting somewhere.

I agree that time is neither a wave or a particle. Now this sets up the next question. As far as I know, everything that can be sensed, measured, or experienced is made of either a particle or a wave. Now I could be incorrect and I invite anyone to correct me.

You see this is how I came to the conclusion that time is not a physical thing, and so is not part of the physical universe, and so time is relegated to the understanding that it is just a concept. Do you see where I am coming from now?

This is why I came to this form, so I could discuss this understanding of mine and get it corrected if I am wrong.

If anybody can show me an example of something that is neither a particle or a wave yet exists, I would like to know what it is and what characteristics it has that gives it a specific identity, and how is this non particle, non wave thing is identified?

Again, thank you for getting the ball rolling on this.

 

[atyy]

How does one know this fundamental process is really periodic - no clock to measure it is available! The only way out is to define that process as being periodic. But which kind of process should one use for that?
Stephani, http://books.google.com/books?id=WAW-4nd-OeIC&printsec=frontcover#PPA6,M1

Maybe also try Barbour's "The Nature of Time"
http://www.fqxi.org/community/forum/topic/360

 

[john 8]

Time is not a wave or a particle.

Thank for your response.

Now we can move on to the next step. If you think that time is neither a wave or a particle, do you think that time is a something that is an integral part of this universe that can be effected by and have effects on those things that are part of this universe, such as those things that are made of particles or waves?

If so, what is this time thing?

You see I am of the understanding that in order for anything to be classified as a thing it has to have certain characteristics that identify it as this certain thing. As far as I understand all things that are considered to be a part of this physical universe and are of use or can be used in physics are made of either particles or waves.

If you say that time is measured by a clock so that makes time a real thing, than be more specific. What is being measured exactly and how.

You see voltage is a measurement of the action of electrons, this specific measurement of electrons is given the label of a measurement of voltage. So that measurement involves waves or particles depending on what school of thought you prescribe to.

A measurement of mass or weight involves atoms, electrons and such. So we are measuring the interaction of gravity on particles.

A measurement of light intensity involves waves.

A measurement of a car's speed involves an object made of atoms. Take away the atoms and there is no measurement.

A measurement of sound involves air particles.

I could go on but I think you get the point.

In fact if you think about it, measuring devices are made of particles, and in order for any measurement to take place, what is being measured has to have the ability to interact and influence those particles.

So if you say a clock measures time than what exactly is the force, energy, substance, whatever you want to call it, that is being measured and causing a change in the measuring device. If you think a clock is a measuring device, then that means that it is detecting a thing in some manner.

What would be this thing?

It would be better to just stick to giving an example of something that is neither a particle or a wave and yet is identifiable as a thing that exists in this universe. that is if you still think time exists as a thing that can influence other things in this universe, yet is not a particle or wave.

Just to be perfectly clear, I have told you what I thought time was not.

Since time is not a particle or wave, I consider time to be just a man made concept, and the idea of time only exists as a consideration nothing more.

Please correct me if I am wrong and set me straight.

 

[john 8]

The argument with john 8 appears to be purely semantic. I agree with him tha time is neither a wave nor a particle.

The discussion with meteor9 looks more interesting.

Thank you for your reply.

Do you think that time is a thing that is measured by clocks?

Do you think time is something that can physically dilate?

Do you think that time is a thing that exists as a specific thing that has special characteristics that identify it as time?

Do you think that time can have an influence on other physical things and yet not be a particle or a wave?

 

[john 8]

Energy is force times distance, force is mass times acceleration, and acceleration is change in velocity over time. So energy is mass times change in velocity over time times distance. So space and time are a fundamental part of the very definition of energy. You will have to do more than just shrug and say that they have nothing to do with each other.

Holy crap man!

Where do I start with this complete misunderstanding, misinterpretation, misleading mess?

Your line of “logic” is amazing. Is this really how your mind works?

I am sorry to be so critical but you have been disagreeing with me on my assertion about time as though you were knowledgeable in the basics of physics.

Please. Please. Please. Review your physics and clear up any misunderstood words that you have.


I am going to do you and whoever else reads this a favor and straighten out your mess.

First, your definition of energy is wrong.

If we were to apply your definition of energy to the real world it would not jive.

You say energy is force times distance. So watch what happens in the real world according to your definition.

I place my hand on a wall and push against it, I am using a force against the wall. The wall does not move so distance is zero. Force times zero distance equals zero. According to your definition there is no energy being used.

A car pushing against a bulldozer at full throttle, the car and the bulldozer do not move, no distance, so no energy? I do not think so.

Here is a good definition of energy per “The Essential Dictionary of Science”

Energy; Capacity for doing work. This work may be as simple as reading a book, using a computer, or driving a car.
Without energy no activity is possible. Energy can exist in many different forms. For example, potential energy is energy deriving from position; thus a stretched spring has elastic potential energy, and an object raised to a height above the Earth’s surface, or water in an elevated reservoir, has gravitational potential energy. Moving bodies possesses kinetic energy. Energy can be converted from one form to another, but the total quantity in a system stays the same (in accordance with the conservation of energy principle). Energy cannot be created or destroyed. For example, as an apple falls it loses gravitational potential energy but gains kinetic energy.


There are many other sources to get the correct definition of energy.

So space and time are a fundamental part of the very definition of energy. .

DaleSpam, I can site many definitions of energy that do not have space and time as a fundamental part of energy. You have made up your own definition of energy.


Your definition of force needs work.


I suggest that those who want to know the correct definition of force look to a reliable dictionary.

So DaleSpam, now that I cleared that up would you like to respond to meteor9 again?

Energy has nothing to do with time neither with space. Why should the definition of energy refer to time,.

If there are any people on this form that think time is a thing that can influence a clock or anything, take note of the underlined part of the definition of energy that I provided. If time is not a particle or wave yet you believe that it is a thing that has influence on this physical universe, you will have to explain how time is not a form of energy.

Thank you DaleSpam for bringing up the topic of energy. You helped me out in explaining my point regarding time not being a thing at all, but is just a consideration.

 

[JesseM]

John, did you think about the analogy between time as measured by clocks and "distance along a path" in a 2D plane as measured by odometers, from post 86 and post 83, and post 64 of this thread? If so could you answer the equivalent questions for odometers/distances along paths? I'll give my own answers below...

Do you think that time is a thing that is measured by clocks?

Do you think that "distance along a path" is a thing that is measured by odometers? I'd be inclined to say "yes" to both questions, although I'm not sure if you may have some specific associations with the words "a thing" that I don't.

Do you think time is something that can physically dilate?

Do you think that distance on a path is something that can physically contract? I would say "no" to both. What can happen is that difference in the t-coordinate between two events in a particular inertial frame can dilate relative to the clock time between these events (if both events happen on the worldline of the clock), and similarly if a car is driving along a path that is slanted relative to the x-axis of a coordinate system on a 2D plan, the difference in the x-coordinate between two points on the car's path can contract relative to the distance between these points as measured by the car's odometer (for example, if you're driving on a straight path that's parallel to the x-axis, then when the odometer increases by 10 miles, the car's x-coordinate will also have increased by 10 miles; but if you're driving on a straight path that's at a 60 degree angle from the x-axis, then when the odometer increases by 10 miles, the car's x-coordinate will only have increased by 5 miles). Since both of these are just contractions/dilations relative to a particular coordinate system, I would say that they should not be called "physical".

Do you think that time is a thing that exists as a specific thing that has special characteristics that identify it as time?

Do you think that distance along a path is a thing that exists as a specific thing that has special characteristics that identify it as distance? For my own answer, again I am not really sure what you mean by "thing" or "exists" here, so without definitions I'm not sure. But I'll say what I said in post 86 of the other thread, The time along a path through spacetime is at least "physical" if you just mean "there's a well-defined physical procedure for determining the amount of 'time' on a path through spacetime, and this procedure gives a frame-invariant answer" (and of course you can say the same about distance along a path).

Do you think that time can have an influence on other physical things and yet not be a particle or a wave?

Do you think that distance can have an influence on other physical things and yet not be a particle or wave? Again I am not sure because it's not clear what you mean by "influence". I think it makes sense to say that odometers "measure distance" but I don't know if that's equivalent to saying "distance has an influence on odometers", and I'd say the same about clocks and time.

 

[Dale]

First, your definition of energy is wrong.

It was not wrong, but it was slightly sloppy. Energy is the capacity to do work, and work is force times distance. All the rest follows.

If we were to apply your definition of energy to the real world it would not jive.

You say energy is force times distance. So watch what happens in the real world according to your definition.

I place my hand on a wall and push against it, I am using a force against the wall. The wall does not move so distance is zero. Force times zero distance equals zero. According to your definition there is no energy being used.

A car pushing against a bulldozer at full throttle, the car and the bulldozer do not move, no distance, so no energy? I do not think so.

These are both correct, no work is being done on the wall and no work is being done on the bulldozer. This is freshman-level Newtonian physics. These kinds of problems often stump naive students on first glance. These are both just simply cases of 0% efficiency, where all of the energy being used is used to do internal work (where there actually is force times distance on the molecular or piston level) and generate heat.

Here is a good definition of energy per “The Essential Dictionary of Science”

Energy; Capacity for doing work. This work may be as simple as reading a book, using a computer, or driving a car.

The definition of energy is correct. As I noted above I was being sloppy. The definition of work is force times distance (dot product) and all of the remainder of my earlier comments follow.

What is the force and the distance you refer to wrt the work done in reading a book?

DaleSpam, I can site many definitions of energy that do not have space and time as a fundamental part of energy. You have made up your own definition of energy.

Please do so then. Any definition of energy using the word "work" involves space and time as a fundamental part of energy as noted previously.

While you are at it, please define "wave". You are in the habit of using very non-standard definitions, so you need to be clear about what you mean. The standard definition of energy (capacity to do work, work defined as force times distance) includes both space and time as does the standard defnition of wave (the wave equation). If you are using the standard definitions please acknowledge it otherwise please post your definition.

 

[Naty1]

This is the funniest thread so far here on Physics Forums...never have I seen so many crazy conclusions and claims...it outlived it usefuless about a hundred or so posts ago...I'm out of here...